Clear /tmp directory

Hello IBM_Systems_Developer,

This RFE was created to replace a request of a CEAC member done before the RFE website was created.

I will contact him and will post his comments later if he has one.

Greetings Rudi

Thank you for taking the time to submit your request. After careful consideration, we know that we cannot deliver your requested enhancement soon, so it is being declined. However, we believe it may have future value, so we will add it to an internal list for us to keep in mind for the future.

The good news is that with the latest BRMS PTF the location /tmp/BRMS is no longer used.

We understand the requirement including there are varying opinions. We are still investigating and considering various options.

Hello IBM_Systems_Developer,

Please allow me to comment on your 3 suggested solutions.
For 1, 2 and 3 timing is the question here, when do you perform these tasks?
If your system is setup as delivered by the time you reach the statements added in your startup program TCP/IP and it's servers might already have started. So the /tmp directory may already be used by some of the started servers.

Can you please tell me what the right timing is to execute what you suggested? If possible without turning everything upside down and switching to start TCP/IP yourself, because we see vendors who rely on this by adding autostart jobs to the subsystem QCTL.

Greetings Rudi

Please consider UNIX standards & prior comments here before stating what you want to happen. Thanks.

Clearing /tmp during IPL should only be an option unless BRMS also moves the BRMS logs to a 'BRMS' directory or some other directory.

Thank you for submitting this request.

While the open source community may expect /tmp to be cleared every time an IPL is performed on the IBM i, the traditional users will not. Clearing /tmp is not an operation we would perform by default. In addition to the many options below, we could consider adding a non-default mechanism to clear /tmp automatically during IPL.

There are some straightforward options for users to achieve this today.

1. As suggested in a comment in this RFE. Add the Remove Directory (RMDIR) command in your startup program. You may also consider the Remove Link (RMVLNK) command.
RMDIR DIR('/tmp/*') SUBTREE(*ALL)
RMVLNK OBJLNK('/tmp/*')

2. Use the clrtmp -- Clear the /tmp directory Qshell utility in your start up program. This is suggested in the documentation for this utility

3. Create a temporary user-defined file system (UDFS) and mount it over /tmp. Add the Add Mounted FS (MOUNT) command to your startup program. The system will delete all temporary objects for this UDFS when it is unmounted, Reclaim Storage (RCLSTG) on *SYSBASE is performed, or an IPL of the IBM i is performed. Additional information on temporary user-defined file systems can be found here:
https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_73/ifs/rzaaxudftempudfs.htm

As in politics the best way to get this going is a compromise:

So the best option is probably to add this to the command "CHGIPLA" and set it by default not to clear "/tmp". Just for those have stored permanent data here. If the attribute for clearing "/tmp" does not need to be reset after every IPL I hope everybody can live with this.

There's doing things blindly & then there's correcting wrong behavior.. the two are orthogonal. If vendors need time to clean up their code, then add an environment variable, set it to current behavior by default initially, and in a future release switch the default to the correct behavior.

Due to processing by IBM, this request was reassigned to have the following updated attributes:
Brand - Servers and Systems Software
Product family - Power Systems
Product - IBM i
Component - IFS (Integrated File System) and Servers
Operating system - IBM i
Source - COMMON

For recording keeping, the previous attributes were:
Brand - Servers and Systems Software
Product family - Power Systems
Product - IBM i
Component - System Management
Operating system - IBM i
Source - COMMON

The CAAC has reviewed this requirement and recommends that IBM not implement this request. Over time, many application vendors have used /tmp in various ways that would make it inadvisable to blindly clear it.

Background: The COMMON Americas Advisory Council (CAAC) members have a broad range of experience in working with small and medium-sized IBM i customers. CAAC has a key role in working with IBM i development to help assess the value and impact of individual RFEs on the broader IBM i community, and has therefore reviewed your RFE.

For more information about CAAC, see www.common.org/caac

For more details about CAAC's role with RFEs, see http://www.ibmsystemsmag.com/Blogs/i-Can/May-2017/COMMON-Americas-Advisory-Council-%28CAAC%29-and-RFEs/

Nancy Uthke-Schmucki - CAAC Program Manager

Hello PederUdesen,

For me /tmp is the IFS equivalent of the library QRPLOBJ. That library is cleared every IPL.
There are several products, including IBM software which use /tmp to store date which is not really temp data. Just to name two :the BRMS, the flight recorder data, the Flash Copy Toolkit, logging data.
Other IBM software like the Must Gather Tool and Administration Runtime Environment also /tmp for temporary data. In the Open Source world /tmp is cleared during a reboot, for me it makes sense to follow that standard.

If you have data in /tmp which you do not want to get lost, I wonder what it is and why you put it there?

Greetings Rudi

This should definitely be optional.

The COMMON Europe Advisory Council (CEAC) has reviewed this requirement and recommends that IBM view this as a high priority requirement that is important to address.

Background: The CEAC members have a broad range of experience in working with small and medium-sized IBM i customers. CEAC has a crucial role in working with IBM i development to help assess the value and impact of individual RFEs on the broader IBM i community and has therefore reviewed your RFE.

To find out how CEAC help to shape the future of IBM i, see CEAC @ ibm.biz/BdYSYj and the article "The Five Hottest IBM i RFEs Of The Quarter" at ibm.biz/BdYSZT

Therese Eaton – CEAC Program Manager, IBM

L.S.,

The issue is the timing here, because IBM i is using /tmp also. Tell me at what exact moment is it safe to clear this directory? The start of TCP/IP is by default no longer in the startup program, so /tmp might be already used.

Apart from that you command is a delete of this directory. Assuming it will be recreated afterwards is also something I wonder if it will happen.
If you use BRMS that will also delete the BRMS Flightrecorder in the directory /tmp/brms which is something you do not want. So this issue is more complicated the more you study it ;-)

Greetings Rudi

Why not use RMDIR DIR('/tmp/*') SUBTREE(*ALL) in QSTRUP if you wish so ?